[Coud]

no, what the mouseover does is you mouseover something, click the macro and the action occurs

eg if i want to remove curse i mouse over playerA frame and click macro and the curse is removed

Targeting MT
mouse over PLAYER_A frame
"remove curse mouseover macro"
"starts casting heal on MT"

this opposed to

Click PLAYER_A frame
press "remove curse"
click MT frame
"cast heal"


first example never stopped targeting the MT, 2nd example i did.

as mage you can make a macro that casts "remove lesser curse" using mouseover and mindlessly mash it in molten core on several boss fight. as a druid you can turn all your instant cast hots in mouseover macros making healing easy ( or easier ).